float IpdScaleFunction(float latitudeNormalized)
{
// return 1.0f; // Most basic, has discontinuities at poles
// return 1 - latitudeNormalized * latitudeNormalized;
// First constant is 1/(1 - 1/e^(-1)), second constant is -e^(-1)/(1 - e^(-1)),
// necessary to satisfy f(0)=1 and f(-1)=f(1)=0.
return 1.5819767068693265f * Mathf.Exp(-latitudeNormalized * latitudeNormalized) - 0.5819767068693265f;
// return 1.1565176427496657f * Mathf.Exp(-2.0f * latitudeNormalized * latitudeNormalized) - 0.15651764274966568f;
// return 1.0000454019910097f * Mathf.Exp(-10.0f * latitudeNormalized * latitudeNormalized) - 0.00004540199100968779f;
}